Vampire bats — which, as their name suggests, dine on blood — have lost a number of genes in their genome, Scientific American reports, adding that their loss enables the bats to survive on their singular diet.
Subsisting solely on blood raises numerous challenges for the bats. Blood, Scientific American notes, is not rich in nutrients, which means that bats have to take in a lot of it, but that then also means they have to grapple with high levels of iron. Researchers from the LOEWE Center for Translational Biodiversity Genomics in Germany and elsewhere generated a haplotype-resolved vampire bat genome. As they report in Science Advances, the researchers compared that genome to those of two dozen other bats to identify 13 genes that were lost in vampire bats.
These lost genes include taste receptor genes and ones that influence insulin and glycogen production, but also REP15, which is involved in regulating cellular uptake of iron. REP15, the researchers note, is expressed in the gastrointestinal tract, where its downregulation is expected to increase iron accumulation there that can then be excreted. Another lost gene is CYP39A1, which affects the levels of 24S-hydroxycholesterol in the brain, and its loss, the researchers tell Scientific American may have helped boost the bats' memory and sociability.